“Bob was sitting at a table, and when Jay-Z went over to say hello, De Niro told Jay that he never called him back,” a source says.

The source goes on to explain:

Bob wasn’t in any mood to make polite conversation,” the spy says. “He told Jay that if somebody calls you six times, you call them back. It doesn’t matter who you are, that is just rude.”

When Jay-Z tried to make a joke of it, saying he is terrible on the phone, a source says, “De Niro kept telling him that he thinks he’s the man, but that he was disrespectful.’”

“Beyoncé came over, but that didn’t calm Bob down,” the source said, adding that afterward, “It was the talk of the party. Everyone was saying there’s only one star in New York bigger and badder than Jay-Z, and that’s Robert De Niro. He can be quite scary when he’s angry.”

A source close to the Oscar winning actor says the conversation was a private conversation between two men that was overheard and not a big deal.